Cessna 170B N4398B accident near Ravensdale, Washington

Probable cause

A loss of engine power due to fuel exhaustion as a result of the pilot’s inadequate fuel planning.

NTSB analysis

The pilot flew and picked up a passenger for a cross-country flight with multiple intermediate legs and a return destination to his original departure airport. About 1 hour and 20 minutes into the accident leg, about 3,000 ft above the ground, the engine lost all power. The pilot restarted the engine, but it lost all power again about 30 seconds later. The pilot then maneuvered the airplane towards a road for a forced landing. The airplane struck treetops and came to rest upright on a riverbank. Recovery of the airplane revealed that less than a gallon of fuel was retrieved from the two 20-gallon wing fuel tanks.

Postaccident examination of the airplane and engine did not reveal any preimpact mechanical anomalies.

The pilot stated that the engine consumed 12 gallons of fuel per hour and calculated that he had about 3 hours of flight time after filling the aircraft with 34–36 gallons of fuel. Fuel planning calculations revealed that at the time of the loss of engine power, the airplane flew for a total of about 2.8 hours and would have consumed about 42 gallons of fuel. It is likely that the pilot exhausted all usable fuel as he decided to divert to another airport without proper fuel planning.

Text from the NTSB. Open the NTSB docket for WPR22LA166 for the full record.